1. Field of the Invention
This invention involves the drivetrain of an automobile which compensates for movement and misalignment between driving and driven components thereof. Drivetrain components such as clutches, gearboxes or transmissions, and axle drive units are provided with deflection compensation which enables the axis of an input shaft or gear to be angled relative to the axis of the driven shaft or gearing nominally aligned with the input shaft without transmitting substantial deflection loading. The deflection compensation is preferably provided by employing crown involute splines on one of the driving and driven member and mounting the driving and/or driven component so that the centerline of rotation is determined independently of the other component, most preferably by substituting parts without adding additional moving parts to a conventional drivetrain component.
2. Description of the Prior Art
Automotive drivetrain systems typically involve a prime mover such as a motor (which may be of a variety of types, such as a combustion engine, electric or pneumatically powered motor), and may include in various applications a clutch, a gearbox or transmission such as an automatic transmission having a fluid coupling, and a driveshaft and an axle drive unit. Such drivetrain components typically include an input, such as a shaft or gear, and an output, for example a shaft or gear, whereby the rotating speeds of the input shaft and the output shaft may be varied between a direct drive relationship and one or several relatively different speeds through gear reduction. Power generated by the motor is operatively transmitted to the gearbox or transmission, and clutches or flywheels may be located intermediate the motor and the gearbox as is well known in the art. In many automotive applications, the gearbox is connected to the driveshaft which in turn rotatably drives a differential or other axle drive unit for transmitting the power to the axles and wheels of the automobile. Such drivetrains are often of substantial length, such as 2-3 meters. In addition, in many applications the motor and gearbox are of significant mass, and though the motor, gearbox and differential are connected to a frame, such as an automobile chassis or body, relative movement between these components occurs during operation. In addition, the motor, clutch, gearbox or transmission, and/or axle drive unit and axles may not be installed in precision alignment.
As a result of initial alignment variations, movement during operation, and other factors, the inputs and outputs, such as shafts, couplings, gears or other driving and driven members of the drivetrain, may be subjected to different lateral loading where their respective rotational axes are not in linear alignment. This may occur between the engine and clutch, the engine and transmission, the clutch and the gearbox or transmission, or between the axle and the axle drive unit even where the input shaft and output shaft are each journalled by bearings designed for maintaining alignment of the input shaft and output shaft. Two principal consequences of not having the input shaft and output shaft in their designed colinear alignment are typically experienced: one is excessive wear on one of the input and output shaft and their connecting gears and bearings; the other is a loss of power and efficiency in the power transmission. The loss of power and efficiency results from the necessity of a shaft to bend during rotation when its axis of rotation moves or is installed out of alignment. In order for the shaft to turn, some bending must occur, and this bending of high strength steel shafts, even when the bending is visually imperceptible, consumes energy and there is a loss of power delivered from the prime mover to the wheels.